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In Reply to: Cryo Treated posted by waterfall on October 11, 2015 at 21:51:17:
Here are some comments from another debate I found. This guy is definitely a dummy, but admittedly sates he not a vacuum tube guy. He has some interesting points.
"" Cryogenic treatment of metals is common practice to enhance the contrast of the grain structure when viewing it under a SEM; it doesn't alter grain orientation but it does add some separation. Grain structure and orientation can only be altered by cold working or annealing, usually in a controlled atmosphere. Annealing requires heat, but much less than one would expect. The internal temperatures of a vacuum tube are sufficient to anneal the internal components over time.
Since oxygen-free copper was mentioned, I should mention that the only purpose it serves in a wire drawing operation is that its lower impurity level allows it to be drawn to smaller sizes. It is actually slightly less conductive than standard copper but is a necessity when manufacturing ultra fine sizes; standard copper will start to pinch off in the dies around 42 to 44 AWG.
From a metalurgical standpoint I can't really see how it would make any difference. Grain structure can alter conductivity along a given conductor but to my knowledge it has no effect on its emission characteristics. I will admit that in my 20+ year run in the magnet wire business, I never tested anything for emission characteristics so this is only my opinion and should not be considered as fact.
I'm not saying that there isn't a possibility of a difference in performance; just that my experience with metals leads me to question the potential for a difference. I would like to see the results of a controlled experiment before I actually make a judgement.
The only reason for my post was to point out a known application of cryogenic treatment of metals and the effect on the metal itself. Beyond that, I can't draw any solid conclusions. ""
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Follow Ups
- RE: Cryo Treated - waterfall 10/12/1509:29:47 10/12/15 (0)